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Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1988-09-22 to 1988-11-01
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP guideline study. Deviatioins to the updated guideline (adopted 1992): no abiotic sterile and toxicity control, sampling days reduced, reduced test solution

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report Date:
1988

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
yes
Remarks:
, volume of test solution was reduced from 3 to 1.5 liter. The CO2 formed was absorbed with NaOH. An emulsifier was used. CO2 production of the blank was 29.3 mg/l medium
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): sewage treatment plant of CH-4153 Reinach on 1988-09-20
Duration of test (contact time):
28 d
Initial test substance concentrationopen allclose all
Initial conc.:
10 mg/L
Based on:
test mat.
Initial conc.:
20 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
TEST CONDITIONS
1200 mL of the mineral solution with the inoculum were aerated for 24 hours in the test vessel. In 300 mL mineral solution 0.5 ml Nonylphenol 10E05P0 (solution of 31.2 mg in 100 mL bidist. water) and 15 rsp. 30 mg of test substance were added and homogenized. This solution was given to the test vessel which was immediately connected to the CO2 traps.
- Solubilising agent (type and concentration if used): Nonylphenol 10E05P0
- Test temperature: 22 ± 2°C
- Aeration of dilution water: 25 ml/min free of carbon dioxide

TEST SYSTEM
- Culturing apparatus: 2 liter flasks equipped with gas inlet and magnetic stirrer
- Number of culture flasks/concentration: 1
- Method used to create aerobic conditions: magnetic stirrer
- Details of trap for CO2 and volatile organics if used: The CO2 formed by biodegradation was absorbed with NaOH and determined on a carbon analyzer

SAMPLING
- Sampling frequency: On the days 5, 11, 18, 22, 27 and 28
- Sampling method: Determination on a carbon analyzer of the initial CO2 of the 0.05 N sodium hydroxide and the CO2, absorbed in the absorbers filled with 200 ml 0.05 N sodium hydroxide

CONTROL AND BLANK SYSTEM
- Inoculum blank: water as specified in the guideline
- Abiotic sterile control: no
- Toxicity control: no
- Vehicle control: water as specified in the guideline containing 0.5 ml of the Nonylphenol solution
Reference substance
Reference substance:
aniline

Results and discussion

% Degradationopen allclose all
Parameter:
% degradation (CO2 evolution)
Value:
8
Sampling time:
28 d
Remarks on result:
other: in 10 mg/L test substance
Parameter:
% degradation (CO2 evolution)
Value:
2
Sampling time:
28 d
Remarks on result:
other: in 20 mg/L test substance

BOD5 / COD results

Results with reference substance:
94.4% biodegradation in 28 days at 20 mg aniline/L

Applicant's summary and conclusion